| 摘要 |
PURPOSE: To obtain a constant reset time against the change and the momentary interruption of a leading time of a power voltage by providing a circuit discriminating whether or not the power voltage is established up to a prescribed value so as to control a reset time. CONSTITUTION:When a voltage Vb is higher than a reference voltage Va (that is, the power voltage Vcc is established), since an output Vc of a comparator 5 inactivates a discharge circuit 4, the charging of a charging circuit 3 is first started. Only after a charging potential Vd of the charging circuit 3 is higher than the reference voltage Va, the output of an output circuit 6 is the same as the power supply voltage Vcc to release the reset. Since the power voltage establishing is monitored and the result reaches a prescribed potential in this way and then the charging of the charging circuit 3 is started, the reset time is made constant independently of the leading time of the power voltage.
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